class_docstr: A memoizing mapping that retains all deleted items
code: def __delitem__(self, key):
      pass
  
imports: import inspect
  import warnings
  import types
  import collections
  import itertools
  from functools import lru_cache, wraps
  from typing import Callable, List, Union, Iterable, TypeVar, cast
label_desc: Use image node_id 1 for calling the UnboundedMemo obj's underlying member method code with example usage: obj.__delitem__(key) without return types